One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10)(11,16)(12,14)(13,15)(19,27)(23,31)(28,32)(29,30) involution — undirected(2,5)(6,8)(17,18,21,26)(19,28,27,32)(20,25,22,24)(23,30,31,29)(9,11,13,12)(10,14,15,16)(17,19)(18,23)(20,29)(21,27)(22,30)(24,28)(25,32)(26,31)(9,12,13,11)(10,14,15,16)(18,24)(19,27)(20,22)(23,32)(25,26)(28,31)(1,3,4,7)(2,6,5,8)(17,20,21,22)(18,25,26,24)(19,29,27,30)(23,32,31,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.